A few tips about the tube. Put a little air in it so that it holds it's shape when you are getting the first side of the tire on the rim. Then work the tube inside the rim and start the 2nd side of the tire. At this point, air in the tube works against you and makes pinch flats more likely, so let out as much air as you can and run your finger around the inside the tire bead to ensure that the tube will not get pinched between tire and rim. Now work on as much of the 2nd side of the tire as will go easily. Try to let even more air out of the tube by squeezing the 2 side of the tire together.

The last part is difficult, as you discovered, and it really depends on how tightly the rim and tire fit together. Campy rims are a little larger in outside diameter and are known to be hard to mount tires on. Some tires are slightly smaller in bead than others and harder to mount. You could ask your LBS to recommend tires that will be easier for you to mount.

The job becomes easier by getting the proper leverage and using your thumbs effectively. You should be holding the wheel so that the last bit of bead to be pushed over the rim is away from you. I like to squat and lay the wheel flat on my legs. Then use the meaty part of your thumbs, with both thumbs close together and working on the same bit of bead. Push a bit of bead over the rim with 2 thumbs, then move to the next bit. The last push is actually the easiest. The hardest bit is with about 6" left to go.

Good luck. You can do this. Remember, it's not strength that counts, but leverage.